/* vim:set tw=80 expandtab softtabstop=4 ts=4 sw=4: */ /* ***** BEGIN LICENSE BLOCK ***** * Version: MPL 1.1/GPL 2.0/LGPL 2.1 * * The contents of this file are subject to the Mozilla Public License Version * 1.1 (the "License"); you may not use this file except in compliance with * the License. You may obtain a copy of the License at * http://www.mozilla.org/MPL/ * * Software distributed under the License is distributed on an "AS IS" basis, * WITHOUT WARRANTY OF ANY KIND, either express or implied. See the License * for the specific language governing rights and limitations under the * License. * * The Original Code is the Mozilla BMP Decoder. * * The Initial Developer of the Original Code is * Christian Biesinger . * Portions created by the Initial Developer are Copyright (C) 2001 * the Initial Developer. All Rights Reserved. * * Contributor(s): * Bobby Holley * Brian R. Bondy * * Alternatively, the contents of this file may be used under the terms of * either the GNU General Public License Version 2 or later (the "GPL"), or * the GNU Lesser General Public License Version 2.1 or later (the "LGPL"), * in which case the provisions of the GPL or the LGPL are applicable instead * of those above. If you wish to allow use of your version of this file only * under the terms of either the GPL or the LGPL, and not to allow others to * use your version of this file under the terms of the MPL, indicate your * decision by deleting the provisions above and replace them with the notice * and other provisions required by the GPL or the LGPL. If you do not delete * the provisions above, a recipient may use your version of this file under * the terms of any one of the MPL, the GPL or the LGPL. * * ***** END LICENSE BLOCK ***** */ #ifndef _nsBMPDecoder_h #define _nsBMPDecoder_h #include "nsAutoPtr.h" #include "imgIDecoderObserver.h" #include "gfxColor.h" #include "Decoder.h" #include "BMPFileHeaders.h" namespace mozilla { namespace imagelib { class RasterImage; /** * Decoder for BMP-Files, as used by Windows and OS/2 */ class nsBMPDecoder : public Decoder { public: nsBMPDecoder(RasterImage &aImage, imgIDecoderObserver* aObserver); ~nsBMPDecoder(); // Specifies whether or not the BMP file will contain alpha data // If set to true and the BMP is 32BPP, the alpha data will be // retrieved from the 4th byte of image data per pixel void SetUseAlphaData(bool useAlphaData); // Obtains the bits per pixel from the internal BIH header PRInt32 GetBitsPerPixel() const; // Obtains the width from the internal BIH header PRInt32 GetWidth() const; // Obtains the height from the internal BIH header PRInt32 GetHeight() const; // Obtains the internal output image buffer PRUint32* GetImageData(); // Obtains the size of the compressed image resource PRInt32 GetCompressedImageSize() const; // Obtains whether or not a BMP file had alpha data in its 4th byte // for 32BPP bitmaps. Only use after the bitmap has been processed. bool HasAlphaData() const; virtual void WriteInternal(const char* aBuffer, PRUint32 aCount); virtual void FinishInternal(); private: /** Calculates the red-, green- and blueshift in mBitFields using * the bitmasks from mBitFields */ NS_METHOD CalcBitShift(); PRUint32 mPos; BMPFILEHEADER mBFH; BMPINFOHEADER mBIH; char mRawBuf[36]; PRUint32 mLOH; ///< Length of the header PRUint32 mNumColors; ///< The number of used colors, i.e. the number of entries in mColors colorTable *mColors; bitFields mBitFields; PRUint32 *mImageData; ///< Pointer to the image data for the frame PRUint8 *mRow; ///< Holds one raw line of the image PRUint32 mRowBytes; ///< How many bytes of the row were already received PRInt32 mCurLine; ///< Index of the line of the image that's currently being decoded PRInt32 mOldLine; ///< Previous index of the line PRInt32 mCurPos; ///< Index in the current line of the image ERLEState mState; ///< Maintains the current state of the RLE decoding PRUint32 mStateData;///< Decoding information that is needed depending on mState /** Set mBFH from the raw data in mRawBuf, converting from little-endian * data to native data as necessary */ void ProcessFileHeader(); /** Set mBIH from the raw data in mRawBuf, converting from little-endian * data to native data as necessary */ void ProcessInfoHeader(); // Stores whether the image data may store alpha data, or if // the alpha data is unspecified and filled with a padding byte of 0. // When a 32BPP bitmap is stored in an ICO or CUR file, its 4th byte // is used for alpha transparency. When it is stored in a BMP, its // 4th byte is reserved and is always 0. // Reference: // http://en.wikipedia.org/wiki/ICO_(file_format)#cite_note-9 // Bitmaps where the alpha bytes are all 0 should be fully visible. bool mUseAlphaData; // Whether the 4th byte alpha data was found to be non zero and hence used. bool mHaveAlphaData; }; /** Sets the pixel data in aDecoded to the given values. * @param aDecoded pointer to pixel to be set, will be incremented to point to the next pixel. */ static inline void SetPixel(PRUint32*& aDecoded, PRUint8 aRed, PRUint8 aGreen, PRUint8 aBlue, PRUint8 aAlpha = 0xFF) { *aDecoded++ = GFX_PACKED_PIXEL(aAlpha, aRed, aGreen, aBlue); } static inline void SetPixel(PRUint32*& aDecoded, PRUint8 idx, colorTable* aColors) { SetPixel(aDecoded, aColors[idx].red, aColors[idx].green, aColors[idx].blue); } /** Sets two (or one if aCount = 1) pixels * @param aDecoded where the data is stored. Will be moved 4 resp 8 bytes * depending on whether one or two pixels are written. * @param aData The values for the two pixels * @param aCount Current count. Is decremented by one or two. */ inline void Set4BitPixel(PRUint32*& aDecoded, PRUint8 aData, PRUint32& aCount, colorTable* aColors) { PRUint8 idx = aData >> 4; SetPixel(aDecoded, idx, aColors); if (--aCount > 0) { idx = aData & 0xF; SetPixel(aDecoded, idx, aColors); --aCount; } } } // namespace imagelib } // namespace mozilla #endif